<template>
    <el-menu
        :default-active="activeMenu"
        mode="horizontal"
        @select="handleSelect"
    >
        <template v-for="(item, index) in topMenus">
            <el-menu-item v-if="index < visibleNumber" :key="index" :index="item.path" :style="{'--theme': theme}"
            >
                <svg-icon :icon-class="item.meta.icon"/>
                {{ item.meta.title }}
            </el-menu-item
            >
        </template>

        <!-- 顶部菜单超出数量折叠 -->
        <el-submenu v-if="topMenus.length > visibleNumber" :style="{'--theme': theme}" index="more">
            <template slot="title">更多菜单</template>
            <template v-for="(item, index) in topMenus">
                <el-menu-item
                    v-if="index >= visibleNumber"
                    :key="index"
                    :index="item.path"
                >
                    <svg-icon :icon-class="item.meta.icon"/>
                    {{ item.meta.title }}
                </el-menu-item
                >
            </template>
        </el-submenu>
    </el-menu>
</template>

<script>
import {constantRoutes} from "@/router";

// 隐藏侧边栏路由
const hideList = ['/index', '/user/profile'];

export default {
    name: 'TopNav',
    data () {
        return {
            // 顶部栏初始数
            visibleNumber: 5,
            // 当前激活菜单的 index
            currentIndex: undefined
        };
    },
    computed: {
        theme () {
            return this.$store.state.settings.theme;
        },
        // 顶部显示菜单
        topMenus () {
            let topMenus = [];
            this.routers.map((menu) => {
                if (menu.hidden !== true) {
                    // 兼容顶部栏一级菜单内部跳转
                    if (menu.path === "/") {
                        topMenus.push(menu.children[0]);
                    } else {
                        topMenus.push(menu);
                    }
                }
            });
            return topMenus;
        },
        // 所有的路由信息
        routers () {
            return this.$store.state.permission.topbarRouters;
        },
        // 设置子路由
        childrenMenus () {
            var childrenMenus = [];
            this.routers.map((router) => {
                for (var item in router.children) {
                    if (router.children[item].parentPath === undefined) {
                        if (router.path === "/") {
                            router.children[item].path = "/" + router.children[item].path;
                        } else {
                            if (!this.ishttp(router.children[item].path)) {
                                router.children[item].path = router.path + "/" + router.children[item].path;
                            }
                        }
                        router.children[item].parentPath = router.path;
                    }
                    childrenMenus.push(router.children[item]);
                }
            });
            return constantRoutes.concat(childrenMenus);
        },
        // 默认激活的菜单
        activeMenu () {
            const path = this.$route.path;
            let activePath = path;
            if (path !== undefined && path.lastIndexOf("/") > 0 && hideList.indexOf(path) === -1) {
                const tmpPath = path.substring(1, path.length);
                activePath = "/" + tmpPath.substring(0, tmpPath.indexOf("/"));
                this.$store.dispatch('app/toggleSideBarHide', false);
            } else if (!this.$route.children) {
                activePath = path;
                this.$store.dispatch('app/toggleSideBarHide', true);
            }
            this.activeRoutes(activePath);
            return activePath;
        },
    },
    beforeMount () {
        window.addEventListener('resize', this.setVisibleNumber)
    },
    beforeDestroy () {
        window.removeEventListener('resize', this.setVisibleNumber)
    },
    mounted () {
        this.setVisibleNumber();
    },
    methods: {
        // 根据宽度计算设置显示栏数
        setVisibleNumber () {
            const width = document.body.getBoundingClientRect().width / 3;
            this.visibleNumber = parseInt(width / 85);
        },
        // 菜单选择事件
        handleSelect (key, keyPath) {
            this.currentIndex = key;
            const route = this.routers.find(item => item.path === key);
            if (this.ishttp(key)) {
                // http(s):// 路径新窗口打开
                window.open(key, "_blank");
            } else if (!route || !route.children) {
                // 没有子路由路径内部打开
                this.$router.push({path: key});
                this.$store.dispatch('app/toggleSideBarHide', true);
            } else {
                // 显示左侧联动菜单
                this.activeRoutes(key);
                this.$store.dispatch('app/toggleSideBarHide', false);
            }
        },
        // 当前激活的路由
        activeRoutes (key) {
            var routes = [];
            if (this.childrenMenus && this.childrenMenus.length > 0) {
                this.childrenMenus.map((item) => {
                    if (key == item.parentPath || (key == "index" && "" == item.path)) {
                        routes.push(item);
                    }
                });
            }
            if (routes.length > 0) {
                this.$store.commit("SET_SIDEBAR_ROUTERS", routes);
            }
        },
        ishttp (url) {
            return url.indexOf('http://') !== -1 || url.indexOf('https://') !== -1
        }
    },
};
</script>

<style lang="scss">
.topmenu-container.el-menu--horizontal > .el-menu-item {
    float: left;
    height: 50px !important;
    line-height: 50px !important;
    color: #999093 !important;
    padding: 0 5px !important;
    margin: 0 10px !important;
}

.topmenu-container.el-menu--horizontal > .el-menu-item.is-active, .el-menu--horizontal > .el-submenu.is-active .el-submenu__title {
    border-bottom: 2px solid #{'var(--theme)'} !important;
    color: #303133;
}

/* submenu item */
.topmenu-container.el-menu--horizontal > .el-submenu .el-submenu__title {
    float: left;
    height: 50px !important;
    line-height: 50px !important;
    color: #999093 !important;
    padding: 0 5px !important;
    margin: 0 10px !important;
}
</style>
